NEWS OF THE WEEK
AMINE SYNTHESIS ADDS UTILITY ORGANIC SYNTHESIS: Reaction
combines C-H fimctionalization with olefin addition to form new amines
T
HE CATALYTIC REACTION of anN-alkyl aryl amine with an unactivated olefin to produce a (3-branched alkyl arylamine has been carried out for the first time in high yield (J. Am. Chem. Soc. 2007, 129,6690). This reaction, which involves activation of a C-H bond adjacent to the amine nitrogen atom, is anticipated to complement existing strategies for synthesizing amines from olefins. The chemists reporting this advance—Seth B. Herzon and John F. Hartwig of the University of Illinois, Urbana-Champaign—have dubbed the reaction hydroaminoalkylation. This reaction has been reported in the literature before, but until now it hadn't been refined to make it useful to synthetic chemists, according to Herzon and Hartwig. In one example, the Illinois team reacted N-methylaniline with l-octene at 160 °G using a tantalum catalyst, Ta[N(CH3)2]5, to form N-((3-methyloctyl)aniline in greater than 95% yield. The (3-branched product is the sole detectable regioisomer in the reactions, Hartwig notes. That type of reaction selectivity is unusual, he says, because it means that a C-H bond of the methyl group of N-methylani-
CAGED BEAUTY MATERIALS SYNTHESIS: Highly
symmetric Keplerate boasts intriguing magnetic properties
F
ROM THREE SIMPLE ingredients has emerged a complex metal cage structure with arresting symmetries. Although its beauty stands out, the molecule also has shown some intriguing magnetic properties, says Zhiping Zheng of the University of Arizona, one of the molecule's architects. In the synthesis, Zheng and a team of collaborators from China combined La(N0 3 ) 3 , Ni(N0 3 ) 2 , and iminodiacetic acid (IDA) in an aqueous solution, sealed the mixture in a Teflon-coated stainless steel container, and subjected it to a roughly weeklong program of heating and slow cooling. Crystallographic analysis revealed a stunning architecture: a pair of nested, cagelike metal spheres bridged by IDA (J. Am. Chem. Soc, DOI: 10.1021^0726198).
The outer Ni(II) sphere's face of pentagons and
line is activated, rather than the typically more reactive N-H bond or unsaturated C-H aryl bonds. Additional progress needs to be made before the reaction "is truly practical," Hartwig tells C&EN. For example, it will be important to reduce reaction temperatures and to develop reactions involving internal olefins, he says. Hartwig suggests that direct alkylation of saturated nitrogen heterocycles is the most obvious application for the new reaction. The work "is a significant step forward in the functionalization of C-H bonds adjacent to a nitrogen atom," says Brandeis University's Jin-Quan Yu, who has de
